(1) Field of the Invention
This invention relates to lights upon a trailer towed behind a truck or other towing vehicle.
(2) Description of the Related Art
In many instances, and in particular, in agricultural, ranching, or recreational pursuits, a pickup truck is used to tow one of many different trailers. When towing the trailers, it is necessary to have an electrical connection between the pickup and the trailer for the operation of running lights, brake (or stop) lights, turn signals, and utility lights.
In commercial practice today there are many different systems of trailer lights basically ranging from a three wire system to a six wire system. For example, using extremely light trailers such as might be used to haul light boats or the like, a three wire system might be used. I.e., there would be one wire which would be connected to the running lights, often called tail lighs and another wire going to the left turn signal, and a third wire going to the right turn signal. Inasmuch as on automobiles, normally the same electrical connection or wire is used for the brakes as is used for activating the turn signals, this is satisfactory for many instances. In other instances, there would be four wires which would be the above identified three wires plus a ground wire. In the simple three wire system, the metal connection of the trailer hitch is used for the electrical ground or else a separate wire outside of the connections is used for the ground wire. In other systems a five wire system is used where there is a separate brake wire. In many cases where a heavier trailer is carried, such as a horse trailer, there will be an additional a utility wire. The utility would provide power for whatever utilization the owner desired that was provided on the trailer.
There are different connectors or plugs and sockets for each of the three, four, five, or six wire systems.
In some cases, the pickup will be "factory wired", and the wires from the pickup to the connector will be in standardized positions. Occasionally, the trailers will be wired to match the standard system on the pickup. However, other times, neither the pickup nor the trailer is wired according to any standard.
Furthermore, it is not unusual for the pickup to be wired for a four, five, or six wire system and the trailer to be wired and have a connector for a three wire system or some other number of wires other than that of the pickup. It will be understood that it can take considerable time for someone such as a rancher to reconnect the wires so that the left turn signal of the pickup matches the left turn signal of the trailer. If one operator having two trucks and five trailers desires, supposedly, he could have all of his trucks and all of his trailers wired according to the same pattern of connections and all using the same connectors. However, in many instances, the person with the pickup might wish to borrow a pickup or borrow a trailer which is not identically wired, taking considerable time to adapt.
Before this application was filed, the applicant was aware of the following U.S. Pat. Nos.:
______________________________________ Inventor U.S. Pat. No. Issue Date ______________________________________ HUNT 2,660,679 11/24/53 HILS 3,428,334 02/18/69 STEWART 3,497,707 02/24/70 RIVERS 3,628,811 12/21/71 BURKLE 3,915,476 10/28/75 TIBBITS 4,005,313 01/25/77 YOUNG 4,057,310 11/08/77 ______________________________________